To open and close vacuum interrupter contacts, a push rod can be used to hold the contacts in closed position and to exert a force on the contacts. The system can be manufactured by producing a metal part, for example made of a steel or a brass material by machining, and later by embedding the metal part by injection moulding in order to produce a push rod part and, respectively, the push rod. Within the metal hole a spring or a spring washer is installed. The push rod can be installed inside a pull housing of the vacuum interrupter by using an intricate tool to apply a torque using a wrench direct to the metal part (wrench face of the metal part; spring retainer until 4 mm or more) which transfers the torque to the threaded connection between the steel stud of the vacuum interrupter and the metal part of the push rod.
U.S. 2010/0108643 A1 discloses a switching device with a vacuum interrupter chamber in which at least one moving contact piece is arranged. To considerably increase the switching rating and the dielectric strength, it is proposed that two series-connected contact arrangements with a total of two contact levels which can be opened are arranged within the vacuum interrupter chamber.
U.S. Pat. No. 5,069,077 discloses an actuating mechanism for a vacuum type interrupter with a contact spring. The actuating mechanism has a pivotally positioned two-armed lever and a spring which holds the contact force ready and which engages with the lever. The two-armed lever is guided with limited displacement in a bearing in a direction which runs approximately parallel to the actuating direction of the interrupter. The two-armed lever pivots about a bearing bolt around the end of the bolt guiding until the contact elements engage each other.